Threaded replies via REST API time out (selectedMessageGuid parameter)

[BigMacDroid]

Summary: When sending threaded/reply messages via the BlueBubbles REST API
using selectedMessageGuid + method: "private-api", the request hangs and times
out after 10 seconds with no response. Regular messages and reactions work
fine.

Key details:

• BlueBubbles 1.9.9 on macOS Sequoia 15.5, Private API connected
• Simple messages and reactions work perfectly
• Adding selectedMessageGuid and partIndex causes the hang
• No errors in server logs — it just never responds
• Multiple message GUIDs tested, all verified to exist

Likely culprits to investigate:

1. The Private API Helper may have a bug or incompatibility with threaded
   replies on macOS Sequoia/15.5
2. The partIndex value — some users report needing to omit it or use different
   values
3. BlueBubbles 1.9.9 may have a regression — worth checking if there's a newer
   version or if this is a known issue in their GitHub

[1960697431]

遇到类似问题，但更严重：使用 /api/v1/chat/new 创建新聊天时也会超时（10秒+）。

环境：

• BlueBubbles Server 1.9.9
• macOS 26.3.0 (Tahoe)
• Private API 已开启

测试结果：

• ✅ /api/v1/ping 正常
• ✅ /api/v1/server/info 正常
• ✅ /api/v1/chat/query 正常
• ❌ /api/v1/chat/new 超时

收到的消息可以正常推送，但无法主动发送消息。